Nagios is a powerful, enterprise-class host, service, application, and network monitoring program. Designed to be fast, flexible, and rock-solid stable. Nagios runs on *NIX hosts and can monitor Windows, Linux/Unix/BSD, Netware, and network devices.

Ganglia is a scalable distributed monitoring system for high-performance computing systems such as clusters and Grids. It is based on a hierarchical design targeted at federations of clusters. Supports clusters up to 2000 nodes in size.

is a Magical Jelly Bean Keyfinder fork. It is a utility that retrieves the product key used to install Windows from your registry or from an unbootable Windows installation. It works on Windows 9X, ME, NT/2K/XP, and Vista/Win7 and for other software.

l7-filter classifies packets based on patterns in application layer data. This allows correct classification of P2P traffic that uses unpredictable ports as well as standard protocols running on non-standard ports.

iTALC is a free classroom management software which enables teachers to view and control computers in their labs and interact with students. It supports Linux and Windows XP (Vista/7 soon) and it even can be used in mixed environments transparently.